Complex asteroseismology of the $\beta$ Cep/SPB pulsator $\nu$ Eridani: constraints on opacities

TL;DR

This study uses complex asteroseismology to test stellar models of $ u$ Eridani, focusing on pulsation frequencies and flux variations, revealing that different opacity tables are favored for different pulsation modes.

Contribution

It introduces complex asteroseismology as a method to simultaneously fit pulsation frequencies and flux variations, providing new constraints on stellar opacities and parameters.

Findings

Agreement for radial mode flux variation with OPAL opacities.

High-order g mode flux variation favors OP opacity tables.

Enhanced seismic constraints on stellar opacities and models.

Abstract

We undertake another attempt towards seismic modelling of the most intensive studied main sequence pulsators of the early B spectral type, $\nu$ Eridani. Our analysis is extended by a requirement of fitting not only pulsational frequencies but also the complex amplitude of the bolometric flux variation, $f$, related to each mode frequency. This approach, called {\it complex asteroseismology}, provides a unique test of stellar parameters, atmospheres and opacities. In particular, the concordance of the empirical and theoretical values of $f$ we obtained for the high-order g mode opens a new gate in seismic studies of the main-sequence hybrid pulsators. The most intriguing and challenging result is that whereas an agreement of the theoretical and empirical values of $f$ for the radial mode can be achieved only with the OPAL data, a preference for the OP tables is derived from the analysis of the high-order gravity mode.